RpgMaker Style Combat for UE4???

I’m a game Design student and my current project is to try and remake an old failed game. I’ve decided to go with Fausts Alptraum and want to add a combat system, I’ve so far made a tile set and 2.5d character to act as the player. however I need help with how to implement an enemie AI and make a combat system that resembles the old Pokemon games, however it needs to be an actual encounter button rather then random spawning, for example when you come within eyeline of the enemie the combat sequence is initiated